/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil -*- */
/*
 * Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
 *                         University Research and Technology
 *                         Corporation.  All rights reserved.
 * Copyright (c) 2004-2005 The University of Tennessee and The University
 *                         of Tennessee Research Foundation.  All rights
 *                         reserved.
 * Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
 *                         University of Stuttgart.  All rights reserved.
 * Copyright (c) 2004-2005 The Regents of the University of California.
 *                         All rights reserved.
 * Copyright (c) 2007      Los Alamos National Security, LLC.  All rights
 *                         reserved.
 * Copyright (c) 2009-2015 Cisco Systems, Inc.  All rights reserved.
 * Copyright (c) 2013      Intel, Inc.  All rights reserved.
 * Copyright (c) 2015      Research Organization for Information Science
 *                         and Technology (RIST). All rights reserved.
 * Copyright (c) 2018      Amazon.com, Inc. or its affiliates.  All Rights
 *                         reserved.
 * Copyright (c) 2018      Triad National Security, LLC. All rights
 *                         reserved.
 * $COPYRIGHT$
 *
 * Additional copyrights may follow
 *
 * $HEADER$
 */

#include "opal_config.h"

#include <stdio.h>
#include <string.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <errno.h>
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_SYS_SOCKIO_H
#include <sys/sockio.h>
#endif
#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#ifdef HAVE_NET_IF_H
#include <net/if.h>
#endif
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef HAVE_IFADDRS_H
#include <ifaddrs.h>
#endif

#include "opal/runtime/opal.h"
#include "opal/util/net.h"
#include "opal/util/output.h"
#include "opal/util/argv.h"
#include "opal/util/show_help.h"
#include "opal/constants.h"
#include "opal/mca/threads/tsd.h"
#include "opal/runtime/opal_params.h"

/* this function doesn't depend on sockaddr_h */
bool opal_net_isaddr(const char *name)
{
    struct addrinfo hint, *res = NULL;

    /* initialize the hint */
    memset(&hint, '\0', sizeof hint);

    /* indicate that we don't know the family */
    hint.ai_family = PF_UNSPEC;
    hint.ai_flags = AI_NUMERICHOST;

    if (0 != getaddrinfo(name, NULL, &hint, &res)) {
        /* the input wasn't a recognizable address */
        return false;
    }
    /* we don't care what family - all we care is that
     * it is indeed an address
     */
    freeaddrinfo(res);
    return true;
}

#ifdef HAVE_STRUCT_SOCKADDR_IN

typedef struct private_ipv4_t {
    in_addr_t addr;
    uint32_t netmask_bits;
} private_ipv4_t;

static private_ipv4_t* private_ipv4 = NULL;

#if OPAL_ENABLE_IPV6
static opal_tsd_tracked_key_t *hostname_tsd_key = NULL;


static void
hostname_cleanup(void *value)
{
    if (NULL != value) free(value);
}


static char*
get_hostname_buffer(void)
{
    void *buffer;
    int ret;

    ret = opal_tsd_tracked_key_get(hostname_tsd_key, &buffer);
    if (OPAL_SUCCESS != ret) return NULL;

    if (NULL == buffer) {
        buffer = (void*) malloc((NI_MAXHOST + 1) * sizeof(char));
        ret = opal_tsd_tracked_key_set(hostname_tsd_key, buffer);
    }

    return (char*) buffer;
}
#endif

/**
 * Finalize the network helper subsystem
 *
 * Finalize the network helper subsystem.  Should be called exactly
 * once for any process that will use any function in the network
 * helper subsystem.
 *
 * @retval OPAL_SUCCESS   Success
 */
static void opal_net_finalize (void)
{
#if OPAL_ENABLE_IPV6
    if (NULL != hostname_tsd_key) {
        OBJ_RELEASE(hostname_tsd_key);
        hostname_tsd_key = NULL;
    }
#endif
    free(private_ipv4);
    private_ipv4 = NULL;
}

int
opal_net_init(void)
{
    char **args, *arg;
    uint32_t a, b, c, d, bits, addr;
    int i, count, found_bad = 0;

    args = opal_argv_split( opal_net_private_ipv4, ';' );
    if( NULL != args ) {
        count = opal_argv_count(args);
        private_ipv4 = (private_ipv4_t*)malloc( (count + 1) * sizeof(private_ipv4_t));
        if( NULL == private_ipv4 ) {
            opal_output(0, "Unable to allocate memory for the private addresses array" );
            opal_argv_free(args);
            goto do_local_init;
        }
        for( i = 0; i < count; i++ ) {
            arg = args[i];

            (void)sscanf( arg, "%u.%u.%u.%u/%u", &a, &b, &c, &d, &bits );

            if( (a > 255) || (b > 255) || (c > 255) ||
                (d > 255) || (bits > 32) ) {
                if (0 == found_bad) {
                    opal_show_help("help-opal-util.txt",
                                   "malformed net_private_ipv4",
                                   true, args[i]);
                    found_bad = 1;
                }
                continue;
            }
            addr = (a << 24) | (b << 16) | (c << 8) | d;
            private_ipv4[i].addr = htonl(addr);
            private_ipv4[i].netmask_bits = bits;
        }
        private_ipv4[i].addr         = 0;
        private_ipv4[i].netmask_bits = 0;
        opal_argv_free(args);
    }

    opal_finalize_register_cleanup (opal_net_finalize);

 do_local_init:
#if OPAL_ENABLE_IPV6
    hostname_tsd_key = OBJ_NEW(opal_tsd_tracked_key_t);
    opal_tsd_tracked_key_set_destructor(hostname_tsd_key, hostname_cleanup);
#endif
    return OPAL_SUCCESS;
}

/* convert a CIDR prefixlen to netmask (in network byte order) */
uint32_t
opal_net_prefix2netmask(uint32_t prefixlen)
{
    return htonl (((1u << prefixlen) - 1u) << (32 - prefixlen));
}


bool
opal_net_islocalhost(const struct sockaddr *addr)
{
    switch (addr->sa_family) {
    case AF_INET:
        {
            const struct sockaddr_in *inaddr = (struct sockaddr_in*) addr;
            /* if it's in the 127. domain, it shouldn't be routed
               (0x7f == 127) */
            if (0x7F000000 == (0x7F000000 & ntohl(inaddr->sin_addr.s_addr))) {
                return true;
            }
            return false;
        }
        break;
#if OPAL_ENABLE_IPV6
    case AF_INET6:
        {
            const struct sockaddr_in6 *inaddr = (struct sockaddr_in6*) addr;
            if (IN6_IS_ADDR_LOOPBACK (&inaddr->sin6_addr)) {
               return true; /* Bug, FIXME: check for 127.0.0.1/8 */
            }
            return false;
        }
        break;
#endif

    default:
        opal_output(0, "unhandled sa_family %d passed to opal_net_islocalhost",
                    addr->sa_family);
        return false;
        break;
    }
}


bool
opal_net_samenetwork(const struct sockaddr *addr1,
                     const struct sockaddr *addr2,
                     uint32_t plen)
{
    uint32_t prefixlen;

    if(addr1->sa_family != addr2->sa_family) {
        return false; /* address families must be equal */
    }

    switch (addr1->sa_family) {
    case AF_INET:
        {
            if (0 == plen) {
                prefixlen = 32;
            } else {
                prefixlen = plen;
            }
            struct sockaddr_in inaddr1, inaddr2;
            /* Use temporary variables and memcpy's so that we don't
               run into bus errors on Solaris/SPARC */
            memcpy(&inaddr1, addr1, sizeof(inaddr1));
            memcpy(&inaddr2, addr2, sizeof(inaddr2));
            uint32_t netmask = opal_net_prefix2netmask (prefixlen);

            if((inaddr1.sin_addr.s_addr & netmask) ==
               (inaddr2.sin_addr.s_addr & netmask)) {
                return true;
            }
            return false;
        }
        break;
#if OPAL_ENABLE_IPV6
    case AF_INET6:
        {
            struct sockaddr_in6 inaddr1, inaddr2;
            /* Use temporary variables and memcpy's so that we don't
               run into bus errors on Solaris/SPARC */
            memcpy(&inaddr1, addr1, sizeof(inaddr1));
            memcpy(&inaddr2, addr2, sizeof(inaddr2));
            struct in6_addr *a6_1 = (struct in6_addr*) &inaddr1.sin6_addr;
            struct in6_addr *a6_2 = (struct in6_addr*) &inaddr2.sin6_addr;

            if (0 == plen) {
                prefixlen = 64;
            } else {
                prefixlen = plen;
            }
            if (64 == prefixlen) {
                /* prefixlen is always /64, any other case would be routing.
                   Compare the first eight bytes (64 bits) and hope that
                   endianess is not an issue on any system as long as
                   addresses are always stored in network byte order.
                */
                if (((const uint32_t *) (a6_1))[0] ==
                    ((const uint32_t *) (a6_2))[0] &&
                    ((const uint32_t *) (a6_1))[1] ==
                    ((const uint32_t *) (a6_2))[1]) {
                    return true;
                }
            }
            return false;
        }
        break;
#endif
    default:
        opal_output(0, "unhandled sa_family %d passed to opal_samenetwork",
                    addr1->sa_family);
    }

    return false;
}


/**
 * Returns true if the given address is a public IPv4 address.
 */
bool
opal_net_addr_isipv4public(const struct sockaddr *addr)
{
    switch (addr->sa_family) {
#if OPAL_ENABLE_IPV6
        case AF_INET6:
            return false;
#endif
        case AF_INET:
            {
                const struct sockaddr_in *inaddr = (struct sockaddr_in*) addr;
                int i;

                if( NULL == private_ipv4 ) {
                    return true;
                }

                for( i = 0; private_ipv4[i].addr != 0; i++ ) {
                    if( private_ipv4[i].addr == (inaddr->sin_addr.s_addr &
                                                 opal_net_prefix2netmask(private_ipv4[i].netmask_bits)) )
                        return false;
                }

            }
            return true;
        default:
            opal_output (0,
                         "unhandled sa_family %d passed to opal_net_addr_isipv4public\n",
                         addr->sa_family);
    }

    return false;
}

bool
opal_net_addr_isipv6linklocal(const struct sockaddr *addr)
{
#if OPAL_ENABLE_IPV6
    struct sockaddr_in6 if_addr;
#endif

    switch (addr->sa_family) {
#if OPAL_ENABLE_IPV6
        case AF_INET6:
            if_addr.sin6_family = AF_INET6;
            if (1 != inet_pton(AF_INET6, "fe80::0000", &if_addr.sin6_addr)) {
                return false;
            }
            return opal_net_samenetwork(addr, (struct sockaddr*)&if_addr, 64);
#endif
        case AF_INET:
            return false;
        default:
            opal_output (0,
                         "unhandled sa_family %d passed to opal_net_addr_isipv6linklocal\n",
                         addr->sa_family);
    }

    return false;
}

char*
opal_net_get_hostname(const struct sockaddr *addr)
{
#if OPAL_ENABLE_IPV6
    char *name = get_hostname_buffer();
    int error;
    socklen_t addrlen;
    char *p;

    if (NULL == name) {
        opal_output(0, "opal_sockaddr2str: malloc() failed\n");
        return NULL;
    }
    OPAL_DEBUG_ZERO(*name);

    switch (addr->sa_family) {
    case AF_INET:
        addrlen = sizeof (struct sockaddr_in);
        break;
    case AF_INET6:
#if defined( __NetBSD__)
        /* hotfix for netbsd: on my netbsd machine, getnameinfo
           returns an unkown error code. */
        if(NULL == inet_ntop(AF_INET6, &((struct sockaddr_in6*) addr)->sin6_addr,
                             name, NI_MAXHOST)) {
            opal_output(0, "opal_sockaddr2str failed with error code %d", errno);
            return NULL;
        }
        return name;
#else
        addrlen = sizeof (struct sockaddr_in6);
#endif
        break;
    default:
        return NULL;
    }

    error = getnameinfo(addr, addrlen,
                        name, NI_MAXHOST, NULL, 0, NI_NUMERICHOST);

    if (error) {
       int err = errno;
       opal_output (0, "opal_sockaddr2str failed:%s (return code %i)\n",
                    gai_strerror(err), error);
       return NULL;
    }
    /* strip any trailing % data as it isn't pertinent */
    if (NULL != (p = strrchr(name, '%'))) {
        *p = '\0';
    }
    return name;
#else
    return inet_ntoa(((struct sockaddr_in*) addr)->sin_addr);
#endif
}


int
opal_net_get_port(const struct sockaddr *addr)
{
    switch (addr->sa_family) {
    case AF_INET:
        return ntohs(((struct sockaddr_in*) addr)->sin_port);
        break;
#if OPAL_ENABLE_IPV6
    case AF_INET6:
        return ntohs(((struct sockaddr_in6*) addr)->sin6_port);
        break;
#endif
    }

    return -1;
}


#else /* HAVE_STRUCT_SOCKADDR_IN */

int
opal_net_init()
{
    return OPAL_SUCCESS;
}


int
opal_net_finalize()
{
    return OPAL_SUCCESS;
}


uint32_t
opal_net_prefix2netmask(uint32_t prefixlen)
{
    return 0;
}


bool
opal_net_islocalhost(const struct sockaddr *addr)
{
    return false;
}


bool
opal_net_samenetwork(const struct sockaddr *addr1,
                     const struct sockaddr *addr2,
                     uint32_t prefixlen)
{
    return false;
}


bool
opal_net_addr_isipv4public(const struct sockaddr *addr)
{
    return false;
}


char*
opal_net_get_hostname(const struct sockaddr *addr)
{
    return NULL;
}


int
opal_net_get_port(const struct sockaddr *addr)
{
    return -1;
}

#endif /* HAVE_STRUCT_SOCKADDR_IN */
